Simplify wait method assertions

 - The wait for invisibility method is particularly problematic if you
   have bad luck, the element could disappear between the
   element_exists? and find_first().visible? test, giving you a
   NoMethodError
Fix typo
Merge pull request #28 from excepttheweasel/master

Simplify wait methods
added no_element_exists method and tests
Merge pull request #29 from johnwake/master

Tests for no_element_exists
updating history and todo
Adding realms.
Removed dependency on capybara 2.1.0 since that breaks because of find_css issue. Atleast locally. https://github.com/thoughtbot/capybara-webkit/issues/507
removed realm as seperate method - just an alias for page.
Added specs for realm.rb